Generally, every trunked radio communications system has a band plan that defines how radio frequencies of a spectrum are utilized for the communications of the system. A band plan typically defines the frequency range of the spectrum and how channels are defined in the frequency range.
To accommodate the movement of a subscriber in a trunked radio communications system from a first site having a first band plan to a second site having a second band plan, where the subscriber is currently programmed for the first band plan, the subscriber needs to be reprogrammed with the second band plan before the subscriber can use the second site with the second band plan. This may occur if the subscriber is moving in an area served by sites having different band plans. For example, the subscriber may be within the vicinity of a first site having a band plan that adheres to National Public Safety Planning Advisory Committee (NPSPAC) channels in the 821-824 MHz range and move into the vicinity of a second site having a band plan that adheres to NPSPAC channels in the 806-809 range. Moreover, if the second site provides better service, then the subscriber may wish to switch to the second site but may not be able to unless the subscriber is able to operate with the second band plan.
Further, if a band plan of any specific site is changed (e.g. by reprogramming of the site), then all the subscribers associated with the site will not be able to operate until the subscribers are also reprogrammed to operate with the new band plan.
Currently, reprogramming of subscribers requires manual effort by radio service personnel so that the radio service personnel have direct physical access to a given subscriber. It is not always convenient or even possible, however, for all of the subscribers in a given system to be brought, more or less simultaneously, to a common location to permit the physical installation of a new band plan. As a result, the logistic challenge of reprogramming a new band plan for many subscribers can be challenging.
Thus, there is a need for an improved method of indicating a band plan in a trunked radio communications system.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.